Re: [M100] M100 repair video

Very nice job. I have not had a xtal failure that was interesting. Would be good to have a video on repairing the LCD screen, that is one where I have the most problems. Also perhaps a one to deal with keyboard issues? Looking forward to the next one. From: M100

Re: [M100] M100 repair video

I have been using a ketchup/condiment bottle as an alcohol dispenser :) From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of Kevin Becker mailto:ke...@kevinbecker.org>> Reply-To: mailto:m...@bitchin100.com>> Date: Wednesday, January 29, 2020 at 7:20 PM To:

Re: [M100] DIY REX quandry

Yes mixed up my sizes 102 vs 100. Not sure I suspect they are so close that with flexible pins you would not notice. I know I have two different '80s 3rd party modules sizes they were hard to swap around when I was testing. From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of

Re: [M100] DIY REX quandry

Yes, at least on the M100s I have upgraded. There seems to be a 650mil and 600mil version of the RAM socket width. I think the 650 is on the older boards. Later it appears to have become 600mil – the standard size. They are so close that it is not really noticeable. I only ‘discovered’ it

Re: [M100] DIY REX quandry

DIY REX quandry thanks, great tip. I hadn't thought about damage to the socket. How do you actually accomplish this? Seems that you need to do 2 snips per pin. In the drawing each end of the pin is connected to a frame. On Sun, Jan 26, 2020 at 3:19 PM Fugu ME100 mailto:b4me...@hotmail.com>>

Re: [M100] REXCPM & M100 CP/M

Will it be able to use a DVI for screen output? On 25/1/20, 8:39 PM, "M100 on behalf of Philip Avery" wrote: >That will work with M100 CP/M. Same CP/M command (Stat) will redirect >'screen' output to the printer port if you like. >In fact you can redirect keyboard input from the serial as well,

Re: [M100] DIY REX quandry

I have good experience using TE Connectivity AMP Connectors 1544210-2 (Digikey A117856CT-ND or Mouser 571-1544210-2) on RAM modules or other boards that are to be plugged into a socket. Use an old IC socket to align the strip and solder, then snip off the top part makes for a very neat final

Re: [M100] Request for info on RS DV Interface

I have no experience with the DVI drives, but having replaced quite a few caps on model T boards over the years it should be one of the first tasks to keep the drives happy. The description in the link sounds very familiar especially looking for damaged tracks under and around the caps.

Re: [M100] Request for info on RS DV Interface

Probably the easiest and safest :) method is to use an Auto-transformer to step down the UK 240V to the US 120V. They should be available with a UK plug on one side and a US socket on the other you can then simply plug in the DVI unit without touching any live 240V mains - they are generally

Re: [M100] Request for info on RS DV Interface

If you wanted to retain the look/feel you could replace the 120V step down transformer wth a 240V step down. The DVI Service manual does not mention the step down voltage but it might be on the transformer. You would also have to replace the AC wiring, switch and fuse holder with 240V rated

Re: [M100] Club100 Personal Libraries Working again

Thanks! Great to have them back. Preview would be nice to get working again, or just working :-) From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of Stephen Adolph mailto:twospru...@gmail.com>> Reply-To: mailto:m...@bitchin100.com>> Date: Sunday, January 12, 2020 at 11:11 AM

Re: [M100] Issue with sd2tpdd

Just tried the dice program and it loaded and saved without problems. It did have a syntax error in line 1020 :) This was using the REX vanilla TSDOS ROM version with an ATMEGA "TPDD Drive", however it was not using SD2TPDD. It was using a heavily modified variant of DLPLUS running on a MEGA

Re: [M100] Issue with sd2tpdd

I would probably just use memset rather than the for loop. :) From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of Dan Higdon mailto:therealh...@gmail.com>> Reply-To: mailto:m...@bitchin100.com>> Date: Tuesday, October 15, 2019 at 8:10 AM To: mailto:m...@bitchin100.com>> Subject:

Re: [M100] Issue with sd2tpdd

This is normal behavior it is the 00H - Directory Reference message, requesting the first directory block and subsequent blocks. The byte after the attribute specifies the type. I agree it does look weird when you see it happening. Do you happen to have a link to the MENU.BA file I would like

Re: [M100] M100 only displays black blocks

Must be the fall seasonŠ.. My M100 just did the same thing while in use on A/C power, the picture looks almost identical apart from the white block and it only has two bands. The NiCd has been replaced and a cold reset etc did not change the locked condition. It seems to be stuck in that

Re: [M100] Need help with bad RAM identification and replacement

red the other parts from Digi Key. So... total cost to me was under $25 for everything shipped. This is enough parts to build 3 of them. Not too bad. Thanks for the tip! Chad On Wednesday, August 21, 2019, 07:18:31 PM CDT, Fugu ME100 mailto:b4me...@hotmail.com>> wrote: >From A

Re: [M100] Need help with bad RAM identification and replacement

>From A000H to BFFFH is Option RAM #2 based on figure 3-5 in the 100 Reference >Manual. This would cover the bad RAM. So this looks correct. If it is a Model 100 the modules were available form Arcade Shopper

Re: [M100] M100 display not working, all else seems good

ife! Chad On Monday, August 19, 2019, 10:52:31 PM CDT, Fugu ME100 mailto:b4me...@hotmail.com>> wrote: On my machine it swings from about 1V to around 3.5V. The 1.25V is way too low I feel. Is there a good connection from T23 to pin 4? It sounds as if that line might be disconnect o

Re: [M100] M100 display not working, all else seems good

On my machine it swings from about 1V to around 3.5V. The 1.25V is way too low I feel. Is there a good connection from T23 to pin 4? It sounds as if that line might be disconnect or there is a problem with the contrast voltage generation. Is VR1 giving a good voltage input? From: M100

Re: [M100] M100 display not working, all else seems good

How much is the contrast voltage adjusting? From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of "chadhendrick...@sbcglobal.net" mailto:chadhendrick...@sbcglobal.net>> Reply-To: mailto:m...@bitchin100.com>> Date: Monday, August 19, 2019 at

Re: [M100] M100 display not working, all else seems good

Yes the machine sounds as if it is healthy, even the display is present. The boot up will hang if it cannot read back from the display – so it would not beep. I would guess the contrast line has insufficient swing. From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of

Re: [M100] M100 display not working, all else seems good

This seems very similar to a problem a few weeks ago where the contrast signal was absent on the LCD connector. One of the leaking caps had eaten through the contrast control line. A quick check of the continuity between pin 4 on the LCD connector and the base of T23 would confirm that is

Re: [M100] In the hospital

Sounds like a required upgrade :) Here's to a speedy recovery! On 19/7/19, 8:05 AM, "M100 on behalf of Ken Pettit" wrote: >Hey Gang, > >I had to come to the hospital again on Wednesday because of cardio >issues. After the angiogram yesterday, the Dr. told me I need bypass >surgery, which they

Re: [M100] Non working display on my m100

On my M100 with no screen attached the V2 voltage ranges from about 1.5V to almost 3V. From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of George Hines mailto:mrthreepla...@gmail.com>> Reply-To: mailto:m...@bitchin100.com>> Date: Saturday, July 6, 2019 at 3:48 PM To:

Re: [M100] Non working display on my m100

The contrast voltage appears to be too low if memory serves the voltage swing needs to be greater than 300mV, the manual indicates the swing should be around 4V (pg 38). It could be that VR1 needs cleaning or at least checking out or c106/c105 might have problems. The display sounds like it

Re: [M100] dsub 25 hood that fits

I went for a slightly different solution and made a level shifter board that fits into the TPDD 8x2 plug on one end with a DB25 towards the Model T, then used an off the shelf straight through serial cable to connect the TPDD to the Model T. Works really well no need to crimp anything just all

Re: [M100] M100 memory

HI Yes they are 8K modules and there are a few options to build or buy new modules :) The Tandy Wiki http://tandy.wiki/Model_100_RAM is a great resource for information on parts etc for the Model Ts. A few people on the list create Model T parts in their spare time, as hobby, they might have

Re: [M100] Non-charger

Sometimes a cold boot can help after a NiCd battery replacement. Then check the Vdd and Vee voltages are +5V and –5V respectively. The voltage on the battery should be about 3.7V if it is charging OK. It could be powering on just the screen is dim. Try powering on, hit return (this takes

Re: [M100] TeraTerm - still not communicating

Yes unfortunately. Just need a male/male adapter. Should be easy to find. After that it should work though. :-D From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of Thomas Morehouse mailto:nutmegfl...@gmail.com>> Reply-To: mailto:m...@bitchin100.com>> Date: Friday, April 5,

Re: [M100] TeraTerm - still not communicating

The M102 serial port has 25pins located on the rear right hand side and labelled RS-232-c with 25 female ‘pins’. The only 9 pin port on the M102 is the barcode reader port located on the mid-left hand side. Just wanted to check that the correct port was being used to connect to the M102 for

Re: [M100] Display goes blank when plugged into power adapter

Which model transformer did you use? I have been looking for a replacement but have not really found one. Thanks! On 2/4/19, 11:28 AM, "M100 on behalf of Josh Malone" wrote: I've also had to replace the transformer on a unit, though that one was exhibiting complete power-on failure.

Re: [M100] Lighter rows of pixels on LCD

I don¹t think you damaged the screen it was probably like that before you touched it. They are very old machines and way beyond their expected EOL. Even fully functional machines can stop working after time in storage. I recently took out my favorite 102 after a few weeks of none use and it

Re: [M100] Lighter rows of pixels on LCD

I have used de-oxit on the edge of the elastomer to pcb contact in the past – very, very sparingly to try and clean the PCB contacts. Then used a piece of stiff card to very very gently push the elastomer in an attempt to clean up the contacts. This tends to work for lines that are blank

[M100] Model 600 [was Re: ebay seller]

I have one at the moment. I would have to agree wth the comments it is big and heavy – it has a huge NiCad built in. The 600 is a curious machine, a 'missing link' from the Model T to the MS-DOS machines. I do not use it all, it needs to sit on a desk it is so heavy unlike my favorite 102

Re: [M100] ebay seller

The second one is actually my design. Although it does not provide 96K only a regular 8K module for the M100. Curious as to how it was copied from OSHpark, they would have to get the gerbers? OSHPark provide 3 for $6.30 and free shipping, so the ebayer is quite expensive. I guess they

Re: [M100] Rex vs DVI

The DVI-DOS loads from 0xE000 -> 0xF700. It also taps into the command processor for BASIC to add in the extra DVI commands. If REXMGR or anything else writes over those locations with its own jumps etc then the DVI commands will not be found (FC error). It would appear that is what is

Re: [M100] Rex vs DVI

Interesting question, are there any uniquely DVI DOS applications? Or were they simply unique commercial packages e.g payroll, stock control etc, that were never released widely? The TPDD drive seems to be more useful with its portability and plays to the strength of the Model T in its day.

Re: [M100] TPDD emulator on Arduino

Yes the ESP-12 works really well. The ESP-8266 is now integrated with the Arduino IDE so moving code around is a breeze. Although there are still some issues with sleep etc. There are also a bunch of libraries like WiFi Scan, FTP, TELNET, NTP and OTA updating which make it quite simple to

Re: [M100] Unable to Load TEENY to MT

The REX board needs to be seated all the way down. It should feel firmly inserted into the socket, it might not be making good contact all the way round. The REX programmer will run to completion even if the board is not properly inserted. After running CALL63012 does the machine lock up or

Re: [M100] Unable to Load TEENY to M1

Must admit I have never had that happen, all the faults I have seen usually allow the RF149.co run to completion. I have plugged them in backwards a few times though :-D Especially when trying to debug crashing programmings. I have had problems where the +5V has failed and corrupted a REX,

Re: [M100] Unable to Load TEENY to MT

jho...@pobox.com>> Reply-To: mailto:m...@bitchin100.com>> Date: Sunday, January 27, 2019 at 2:08 PM To: mailto:m...@bitchin100.com>> Subject: Re: [M100] Unable to Load TEENY to MT On Sun, Jan 27, 2019 at 1:48 PM Fugu ME100 mailto:b4me...@hotmail.com>> wrote: *Simp

Re: [M100] Unable to Load TEENY to MT

t; Subject: Re: [M100] Unable to Load TEENY to MT On Sun, Jan 27, 2019 at 12:55 PM Fugu ME100 mailto:b4me...@hotmail.com>> wrote: The RAM TPDD is most likely conflicting with the the REX program. The best method is to use TEENY to download the RF149.CO<https://eur01.safelinks.protec

Re: [M100] Unable to Load TEENY to MT

The RAM TPDD is most likely conflicting with the the REX program. The best method is to use TEENY to download the RF149.CO file. I have never used the RAM TPPD to program a REX. Running the REX programmer to completion should only take around 5mins. The erasing part takes about 20-30s then

Re: [M100] Unable to Load TEENY to MT

Hi Greg TS-DOS is not needed to re-flash the REX. Teeny should be good enough to get the RF149.co across to the model T. The flash program has its own built in DOS which should them pull in the two other ROM files from the ŒmComm Drive¹. Make sure tsd100.bx and RXF149.BR are at the top level of

Re: [M100] M100 stuck on the menu with weird date :o(

Wow that is really corroded, I would replace it. Simply heating the pins of the clock IC and using some new solder would be a good start. Not sure about caps in Australia hopefully someone local can help out with that question. On 9/1/19, 5:23 AM, "M100 on behalf of Eric LK" wro

Re: [M100] another m100 failure (maybe cap? maybe not?)

Did you check the Vee voltage? It should be close to -5V. What you describe sounds very much like a failing -5V rail. But need to confirm with the Vee measurement. It might be time to replace the capacitors :( On 7/1/19, 11:17 AM, "M100 on behalf of Jim Anderson" wrote: >So, I had a VEE

Re: [M100] M100 stuck on the menu with weird date :o(

The +5V looks good, the -5V is a bit low it would be better in the -4.9V to -5.1V region. That should go up when the caps are replaced. It sounds like there is a bad joint somewhere on the board. I think most Model T owners have more than one unit :-D On 7/1/19, 7:48 AM, "M100 on behalf of

Re: [M100] M100 stuck on the menu with weird date :o(

If fixing the board voltages does not remove the problem the next issue could be dry joints near the clock chip, at least on two machines I repaired that was the problem. It looks like the clock chip was placed as a second op when the boards were made and the soldering was not very good. In

Re: [M100] M100 stuck on the menu with weird date :o(

A quick check is to measure the voltages at the VDD and VEE test points marked on the motherboard, they should be a strong +5V and -5V respectively. From the fault you are reporting it sounds as if the main motherboard voltages are bad. The NiCd should be about 3.7V when the power is off. The

Re: [M100] TPDD 2 request for info

Took a look at the TPDD2 DC/DC convertor schematic in the Manual (Pg 36), the convertor is very similar in operation to that in the Model T. There could be a number of problems that are causing the hot transformer: The DC/DC convertor is isolated from everything else when it is being powered

Re: [M100] Model 100 power adapter

I thought the Model T’s where center negative? :) The T1133-P5N-ND Digikey 6V 1A power supply seems to work well as a replacement. Most of the ‘brick’ supplies cannot be easily repaired best to seek out a new one. Check that the output is 6V using a voltmeter if not then the supply is

Re: [M100] Building a run of TPDD cables using Rick's design

I plan to build one hopefully to confirm (or not) that my TPDD drive is OK and the original cable is bad. The drive gives intermittent results which I think might be related to a bad cable or connector - it could be the header on the drive PCB. Hoping this cable will provide the necessary

Re: [M100] project updates.

To: mailto:m...@bitchin100.com>> Date: Friday, November 23, 2018 at 8:46 AM To: mailto:m...@bitchin100.com>> Subject: Re: [M100] project updates. interesting. do you have a disassembly? On Fri, Nov 23, 2018 at 11:27 AM Fugu ME100 mailto:b4me...@hotmail.com>> wrote: The I2C s

Re: [M100] project updates.

The I2C serial EEPROM will need to hold the M100/T102/T200 boot code, M100/T102 Disk BASIC Code and the T200 disk BASIC code (2 parts) which is probably not a lot of bytes by todays standards :-) The Disk BASIC also goes out to read the version info from the DVIs own boot code which is an

Re: [M100] M100 dead - looking for causes of low VEE

Low Vee is most likely caused by bad caps on the -5V line. The loss of -5V after a few seconds is a typical symptom as is the common problem of the LCD fading in and out over time. If you replace the -5V caps it should bring the machine back to life. I would also suggest replacing all the caps

Re: [M100] Tandy Model 100

Hi The failure you describe is not one I have seen. The two LCDs that failed in my machines had horizontal bars of slightly darker contrast. When the contrast was varied the bars remained slightly darker than the rest of the screen. Eventually the -5V dropped to -2V as I assume the current

Re: [M100] Tandy Model 100

on and off a few times in order to get it to come on. > >Thank you, > >> On Oct 12, 2018, at 11:57 AM, Fugu ME100 wrote: >> >> Hi >> >> The voltages look good. I usually replace C86 too it is part of the -5V >> output circuit. >> >> You c

Re: [M100] Tandy Model 100

> >Thank you, > >> On Oct 11, 2018, at 10:27 PM, Fugu ME100 wrote: >> >> Hi >> >> What are the symptoms you are experiencing? >> >> VR1 could go bad but it could also be due to oxidation on the resistors >> tracks. People have tr

Re: [M100] Tandy Model 100

Hi What are the symptoms you are experiencing? VR1 could go bad but it could also be due to oxidation on the resistors tracks. People have tried to use contact cleaner to revive them. Might be worth looking into trying that option first? On 11/10/18, 3:57 PM, "M100 on behalf of Rafael

Re: [M100] Screen Flickering?

Can you check your –5V rail? It should be a solid –5V +/- a few %.Might also want to check the +5V rail. If the –5V is low or is very unstable then…… It is most likely due bad electrolytic caps. The contrast on the screen is controlled by the –5V. Unfortunately the caps will need to be

Re: [M100] New Age Digital Storage Box (NADSBox)

Using the Arduino IDE the F() macro or equivalent is essential to store text strings otherwise you will run out of RAM fast. The SD-Card Library that is part of the IDE is a memory hog too.It does not work well on the smaller ATMEGA parts with only 2K of memory especially if you want to

Re: [M100] DVI or modern equivalent

Here are my thoughts on the DVI :) All you really need is the service manual and user manual, the DVI operation is easy to reverse engineer from those two documents. The ŒZ80¹ DVI code is actually on the DVI boot disk. When the DVI powers on it boots from the floppy disk to load the operational

Re: [M100] Tandy 200 RAM modules

There is also a single RAM version with an easier to solder SOIC part. https://oshpark.com/shared_projects/naMPAS3A They do come and go from eBay, just need to look out for them. From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of Brian White mailto:bw.al...@gmail.com>>

Re: [M100] New Age Digital Storage Box (NADSBox)

That sounds great. What sort of current draw are you getting? Quite curious. From: M100 on behalf of Brian White Sent: Friday, August 24, 2018 20:12 To: m...@bitchin100.com Subject: Re: [M100] New Age Digital Storage Box (NADSBox) I was playing with the

Re: [M100] New Age Digital Storage Box (NADSBox)

At least for an ATMEL MEGA not much power at all especially if it is run at 4MHz. The biggest rated current draw on the TPDD emulator is the SD card which is spec’d at around 100mA while writing to the flash, but is a little manufacturer dependent some are better than others. The TPDD

Re: [M100] I/O error with disk drive

Have you tried a cold boot of the model T? The drive makes shows no activity at all? No front light or spinning disk? You could check the serial interface is good as you might of seen from Josh’s thread the serial port can and does fail. If this is a TPPD-1 drive could also check the DIP

Re: [M100] Backup ROM

You could try this utility http://www.club100.org/memfiles/index.php?===Steve%20Adolph/ROM2S It will dump the ROM as an ASCII HEX file to a TPDD device. There are online utilities that can convert it to a binary file that could be loaded into a REX. I have used it to read mystery OPTROMs

Re: [M100] What would it take to build a modern DVI?

The DVI boot code could run on a Z80 emulator however it would be quite a lot of work and the DVI boot code is heavily intertwined with the CRTC and FDC chips as to make it a fruitless exercise. The boot code on the DVI actually formats the sectors for the disk and simply uses the FDC to

Re: [M100] Ask a silly question

I did reverse engineer around 60% of the boot code of the DVI last year to work out how the Video and Floppy were used – most of it is very low level interface software for the FDC chip and some spaghetti code to control the graphics chip. Quite a lot of corners cut and some neat ways to deal

Re: [M100] tpdd mcomm setups

But I have a handful of REX modules. Just contact me directly off list to arrange shipping. :-) From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of Tom Dison mailto:fretina...@gmail.com>> Reply-To: mailto:m...@bitchin100.com>> Date: Monday, July 23, 2018 at 10:27 AM To:

Re: [M100] Model 100 LCD doesn't work

OK great! I think it is in the user manual  From: M100 on behalf of Nathan Misner Sent: Sunday, July 22, 2018 00:01 To: m...@bitchin100.com Subject: Re: [M100] Model 100 LCD doesn't work Holy shit, thank you! The Ctrl+Break trick got it powering on! I

Re: [M100] Model 100 LCD doesn't work

Swap the leads around on the meter :) the black wire to the -ve voltage and the red to gnd. You could also try a cold boot, just in case. Hold ctrl-break and power on. The NiCd battery is in good health? From: M100 on behalf of Nathan Misner Sent:

Re: [M100] SD2TPDD Project

The Teensy + USB dev card + SD Adaptor should work OK, but it may need a full RS232 I/F + driver. The Arduino Mega is more than enough so should be fine on a Teensy. I pushed it to an ESP12 which was fun :) From: M100 mailto:m100-boun...@lists.bitchin100.com>> on behalf of Lee Olivares

Re: [M100] SD2TPDD Project

tion.outlook.com/?url=https%3A%2F%2Fyoutu.be%2Fi5MNLTc7YhY=02%7C01%7C%7C8520cc7a24784a07629c08d5ef586408%7C84df9e7fe9f640afb435%7C1%7C0%7C636678085265205176=JxZ2i820N2kQdOUDCzmLoCi4gD59%2B203LGCRPUICoRk%3D=0> - Lee Olivares - (909) 437-0250 - The Future or Bust. On Jul 21, 2018, at

Re: [M100] SD2TPDD Project

I used the FatFS http://elm-chan.org/fsw/ff/00index_e.html file system for the SD card, it is much more flexible and avoids the nasty file and directory rename issues. It will easily fit in a Mega – I think it was about 18K or less compiled. The Arduino SD.h has a few bugs in it that have

Re: [M100] Model 100 LCD doesn't work

You may have already checked but make sure the –5V is good and that the contrast pot is working sometimes they do not work so the screen is in low contrast mode = not visible but still working. You should be able to see the screen go almost entirely black as you turn the contrast pot or the

Re: [M100] TPDD Specifics

Quite a lot of other TPDD emulation software running on just about everything you could imagine :) Lots and lots of M100 owners past and present have picked it apart so there should be something on the web to help with your work. A quick web search threw up a few links, a not very exhaustive

Re: [M100] Got a DVI and rant about shipping

Sounds familiar I bought an M600 off eBay a few months ago. The outer box was really sturdy however the seller had just placed the unit on top of two pieces of foam packing - it was free to move around the box. The M600 is really heavy with the internal NiCd battery pack. FedEx appear to have

[M100] Unusual OPTROM in T102

Just acquired an eBay T102 with an OPTROM that was not listed in the sale description - surprised to see it there when I was replacing the battery. When called it sets up as TFDC99 in the menu. Trying to run that generates a FF error at 10. It is housed in an EME wrap around PCB and looks like

Re: [M100] odd REX error - anybody run into this?

Might also check that none of the solder joints have gone bad. The board might start out fine but as the solder oxidizes over time a badly soldered joint could fail. Re-programming may resolve the problem but if there is a bad joint it will just happen again or you may not be able to reprogram

Re: [M100] nn - getting back involved.

There are at least two M100 RAM Boards on OSH Park (a DIP version and an SM Version): https://oshpark.com/shared_projects/V0tpeuMg https://oshpark.com/shared_projects/Ra3VwoJo If this is what you are looking for? This design is based on the NEC module from the 1980/90s. Francesco Messineo (on

Re: [M100] Model 102 Black Nothing After Y2K ROM install

Not in AZ  The Elenco are fine I was thinking of getting one to put in my tool box. From: M100 on behalf of Greg Swallow Sent: Tuesday, June 5, 2018 05:35 To: m...@bitchin100.com Subject: Re: [M100] Model 102 Black Nothing After Y2K ROM install Will take

Re: [M100] Model 102 Black Nothing After Y2K ROM install

ll try and do appreciate your help. > >Thanks, > >GregS <>< > >- Original Message - >From: "Fugu ME100" >To: m...@bitchin100.com >Sent: Monday, June 4, 2018 8:35:36 PM >Subject: Re: [M100] Model 102 Black Nothing After Y2K ROM install > >

Re: [M100] Model 102 Black Nothing After Y2K ROM install

: Tuesday, June 5, 2018 04:07 To: m...@bitchin100.com Subject: Re: [M100] Model 102 Black Nothing After Y2K ROM install I got VDD +5VDC, VEE -5VDC, and VB of +5VDC. No 3.6VDC on VB. - Original Message - From: "Fugu ME100" To: m...@bitchin100.com Sent: Monday, June 4, 2018 7:06:33 PM S

Re: [M100] Model 102 Black Nothing After Y2K ROM install

It does sound like there might of been some static damage on the board. The ROM shares lines with the RAM wonder if a RAM has fried? Or a buffer? On the M100 the Vdd, Vee, Vb and GND lines are marked so it is quite easy to check the +5, -5V & +3.6V are on the board OK.

Re: [M100] Model 102 Black Nothing After Y2K ROM install

The 102 Ref manual is on this page http://www.club100.org/library/libdoc.html of the club 100 site. This should help  Does it work with the original ROM in the socket? From: M100 on behalf of Greg Swallow Sent: Monday, June 4, 2018 22:50 To:

Re: [M100] SPAM-LOW: Re: New member - question on 'half' alive Model 100

That’s great. Pleased to hear you tracked it down - another 100 survives :) Now you have two and that’s how it all starts…. If you want to build RAM modules for the M100 I have two RAM PCBs on OSH Park: SMD Version and DIP version. The design is based on the old NEC modules.

Re: [M100] Rex startup time

After CALL 63012 the return to the menu with REXMGR loaded should take ~1s it is almost instant. You may also want to try a cold boot just in case something is in the RAM. If it is hanging (and the board is installed correctly) then there is most likely a dry/bad joint on the Flash memory or

Re: [M100] SPAM-LOW: Re: New member - question on 'half' alive Model 100

The address could be stuck internally on the RAM so the address line would appear OK externally. The fact the ROM runs correctly with the shared Address line would indicate the address lines are generally OK. It could be floating on the module as you suggest, look to see if there is any

Re: [M100] SPAM-LOW: Re: New member - question on 'half' alive Model 100

If A4 is stuck at 0 (or 1) then the SP and copy location would overlap, eg F5F0H would become F5E0H and overwrite the stack area - at least 6 bytes of it. The RAM modules are made up of 4 ICs so it it possible that only the top most RAM has a fault the others could be fine. If the RAM

Re: [M100] SPAM-LOW: Re: New member - question on 'half' alive Model 100

Does it only execute the loop once and get stuck for the first time at 2574H? The 49H in the data dump is most likely the C9H for the RET. The next two byte are the return address from the stack. They could be 0A57H, 0AD7H, 8A57, 8AD7H or other permutations. As this routine is writing to

Re: [M100] Tandy Model 102 Portable keyboard issue.

There is a diode associated with the key it could of failed. I think the diodes are on the top of the board so you may have to trace out carefully to find the diode for the C-Key. I notice the solder points underneath don't line up exactly to the top.

Re: [M100] Files XFER

One option is to run Mcomm on the PC to act as a TPDD Server and use the null modem cable to connect the PC and M100. http://www.club100.org/memfiles/index.php?===Kurt %20McCullum Mcomm can inject RAM TS-DOS or with the REX you can use that OPT ROM version. This should allow you to read and

Re: [M100] Replaced NiCD with NiMH

The motherboard hooks under the clips on the 102  If left on top the case will not close properly. The 100 and 102 are a breeze to work on compared to the 200. Just getting the screen cable detached is almost impossible, reattaching is a nightmare. There may be a trick but it was beyond

Re: [M100] 8K RAM module

ng the soldering flux is a must. I've measured up to 15 uA of >> standby current on badly cleaned modules. YMMV. >> Glue logic *must* be 74HC family, it has a suitable current draw at >> 3.3V standby and suitable speed. In one case I've used 74AHC and it >> worked well t

Re: [M100] 8K RAM module

You could try https://www.arcadeshopper.com/wp/?page_id=11#!/8k-RAM-module-for-Model-100/p/104430801/category=28313042 They have the M100 modules if you want to buy. If you want to build your own there are PCBs on OSH Park for surface mount and DIP versions. No need for any pillaging :)

Re: [M100] SPAM-LOW: Re: New member - question on 'half' alive Model 100

Yes quite possible a bad 81C55, M15 or keyboard would cause an issue. Try putting in one of the RAM modules see if that helps. Unfortunately the 81C55 also controls the LCD. I should try and see if it is actually reading the ctrl-brk, what if there is a problem with the keyboard or key

Re: [M100] SPAM-LOW: Re: New member - question on 'half' alive Model 100

key sequence it is the CTRL key in the low left, BRK on top row of function keys and the reset button on the back? Thanks again, Jeff From: M100 <m100-boun...@lists.bitchin100.com> On Behalf Of Fugu ME100 Sent: Sunday, May 6, 2018 8:40 PM To: m...@bitchin100.com Subject: Re: [M100] SPAM-L

Re: [M100] SPAM-LOW: Re: New member - question on 'half' alive Model 100

Agreed the lack of NiCd might be having more impact than expected on a machine that expects data to be retained in RAM during power off. From: M100 > on behalf of "John R. Hogerhuis"

Re: [M100] SPAM-LOW: Re: New member - question on 'half' alive Model 100

It is the rising edge of RD that is used to latch the data into the 8085. The ROM has from the falling edge to rising edge to deliver the data. The decoder is level sensitive not edge, so the rising edge will not only disable the ROM but also latch in the ROM data. That looks like it is

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